The present invention relates to a chair, particularly to an office chair. More specifically, it relates to such a chair which has a chair column or vertical support, a seat lower frame which is arranged on the chair column in a height adjustable manner and also rotatably about a vertical axis, a seat support and a backrest support arranged on the seat lower frame rotatably about a horizontal axis, and at least one pressure spring supported on the seat lower frame and the backrest support with an adjustable tensioning.
Chairs of the above mentioned general type are known in the art. Such chairs can be further improved so as to perform an adjustment of the force with which the pressure spring acts on the backrest support, in a simple and space-economical manner.